The 12,500 square foot store, which was opened to the public last Saturday, features rows and rows of items from cuddly Clydes - the Games' mascot - and branded T-shirts to keyrings and haggis.
But critics say the structure would have been far better housed in an empty retail unit instead of dominating the vista of the city's main public square.
A spokesman for campaign group Restore George Square, formed in response to the recent fiasco surrounding the planned revamp of the city centre site, said it was part of an ongoing process which had seen the square increasingly "brutalised" by removing trees and grass to make room for "crush barriers, portaloos and giant tents".
He added: "That George Square is being abused in such a fashion is made all the more frustrating by the dozens of empty retail units that now dominate the city centre.
"The tented superstore is just the latest in a long line of acts of civic vandalism in George Square which make [council leader] Gordon Matheson's 2013 statement, 'the square belongs to the people of Glasgow' a conscious two fingers up at citizens of the city."
A design contest for a £15 million revamp of George Square ended in farce in January 2013 after the judges chose a winner, only for Matheson to immediately announce the council was abandoning the project. The square was subsequently given a more modest £500,000 makeover.
The siting of the Glasgow 2014 superstore has provoked a storm of criticism on social media.
Comments on the Glasgow 2014 Facebook site included: "That superstore is a disgrace for Glasgow. Putting such an ugly thing in one of Scotland's nicest squares is ridiculous." Another said: "I despair for George Square. Long gone is a beautiful civic space, now it's whatever the council wants it to be. One day it's a theme park, the next it's a superstore. This could have filled an empty unit on Buchanan Street, but no, that would make too much sense."
It also triggered debate on the Restore George Square Facebook site, with some describing it as "monstrous" and "an eyesore".
However, one comment noted: "While I wouldn't buy any of the CWG merch [Commonwealth Games merchandise] myself, the tourists will - so [having the superstore] bang in the centre of town near a main station makes sense."
John Pelan, director of the Scottish Civic Trust, which works to improve townscapes, described the store as a "rather ugly" building.
He said: "It is a temporary structure and obviously they need to have some sort of facility in relation to the Games. But they could have been a bit more ambitious so at least it would have been attractive to visitors."
Glasgow City Council confirmed it had given the go-ahead for the superstore but a spokesman referred inquiries about its siting in George Square to Glasgow 2014's organisers.
He added: "The store is creating new jobs as part of a drive which will see several hundred temporary jobs created in Glasgow to handle the sale of official Commonwealth Games merchandise."